Bone marrow is the spongy tissue found in the interior of some types of bones, such as the pelvis, sternum, cranium, ribs, vertebrae and scapulae. Bone marrow is a rich reservoir for pluripotent hematopoietic stem cells, which can be used for stem cell therapy. Conventional bone marrow harvesting devices, such as Jamshidi™ bone marrow needle, generally include a cannula, a handle at the proximal end of the cannula used by a physician to apply force to the cannula, and a stylet with a sharp distal tip to penetrate the bone. During an operation, a physician accesses the target bone, typically from the iliac crest, and applies a suction force to aspirate bone marrow into the cannula.
Bone marrow density varies from patient to patient, where high bone marrow density is typical associated with young age, and calcification of the cancellous bone tissue. Conventional bone marrow harvesting devices may produce insufficient suction force to extract bone marrow in high bone marrow density areas and may be inefficient when a large quantity of bone marrow is required for stem cell therapy or autologous bone marrow transplantation. Several alternative designs have been proposed to facilitate aspiration of bone marrow. For example, U.S. Pat. No. 6,066,153 to Lev and U.S. Patent Publication No. 2005/0209530 to Pflueger each discloses a cutting tip having an “Archimedes' screw” configuration disposed inside the distal end of a cannula. The cutting tip, when rotated, dissects tissue and pushes the dissected tissue proximally, which can be aspirated. In another example, U.S. Patent Publication No. 2007/0198043 to Cox discloses a rotatable aspiration needle and a resilient wire with a curved distal portion disposed in the lumen of the cannula, for agitating or breaking-up bone marrow tissue to facilitate aspiration. However, rotational force may traumatize and/or rupture the stem cells located within the bone marrow, thus requiring a balance to be stuck between causing sufficient disruption of the bone marrow to permit aspiration while reducing trauma to the constituents of the bone marrow.
In view of the foregoing drawbacks of previously known bone marrow aspiration apparatus and methods, there exists a need for a safe and efficacious bone marrow harvesting device that facilitates aspiration of bone marrow, especially in dense tissue, while reducing trauma to the bone marrow constituents.